Cap with opening in the back



FIG. 1 is an enlarged rear/top perspective view of cap with an opening in the back of the present invention;

FIG. 2 is an enlarged front elevation view thereof;

FIG. 3 is an enlarged rear elevation view thereof;

FIG. 4 is a right side elevation view thereof; and,

FIG. 5 is a top plan view thereof.

The dashed lines which define the bounds of the claimed design form no part thereof. 

CLAIM We claim the ornamental design for a cap with an opening in the back, as shown and described. 